Touch fasteners (known commercially as Velcro®, Scotchmate®, Tri-Hook®, etc.) were originally produced using textile technology. Two of the most common types of touch fasteners are hook and loop fasteners and mushroom and loop fasteners.
Hook and loop type fasteners may consist of a pair of textile strips. These textile strips may be mated to form a recyclable closure; one of the mates being a strip of textile fabric having numerous monofilament elements, shaped like hooks, projecting from one surface and the other mate being a textile strip with multifilamented elements woven into loop shaped projections on one surface. When the mating surfaces of these strips are pressed together, numerous hook shaped elements on one strip snare loop elements on the opposing strip and create a temporary, reusable bond. As the strips are peeled apart, the hook elements may deform and separate from the loop elements allowing the fastener to be reused many times.
In the case of mushroom and loop fasteners, the hook type mating strip is replaced with a strip containing numerous monofilament projections having mushroom shaped or blunted heads. The mushroom shaped heads may be formed by heating the tips of straight monofilament projections until a flattened “mushroom head” is formed on each projection. When this strip is pressed together with a strip having loop shaped projections on the surface, the mushroom heads may snare loop elements on the opposing strip and create a temporary, reusable bond. As the strips are peeled apart, the mushroom shaped elements may occasionally deflect and release the loop element. In addition, two strips each having mushroom shaped projections may be engaged together with the blunted heads interacting to form a mechanical bond.
More recently the use of thermoplastic extrusion/molding methods for making touch fasteners has become popular. In the case of hook and loop fasteners, the hook strip may be formed by extruding a polymer into a web-like shape with integral projections, while the loop strip may still be produced using woven, knitted or non-woven technologies. In the case of mushroom and loop fasteners, the mushroom strip may be produced by extruding a polymer into a web-like shape with integral pin-like projections and post forming mushroom-like heads on the pin-like projections.
The use of extrusion/molding technologies for the production of hook type and mushroom type touch fasteners has reduced the manufacturing cost and improved the performance and aesthetics of touch fasteners, thus allowing their use in large volume applications such as tab closures on disposable diapers.
Examples of technologies used for the production of extruded/molded type touch fasteners, include:                Extruding/molding a hook fastener with an integral base where the base may be molded onto a molding roller wherein hooking elements may be molded in discreet cavities. The mold may be opened and closed continuously as it rotates to allow the hooks to be extracted. (See for instance, U.S. Pat. Nos. 3,762,000; 3,758,657 and 3,752,619 to Menzin and U.S. Pat. No. 3,196,490 to Erb.)        Extruding/molding a hook fastener with an integral base where the hooking elements may be molded in discreet cavities and the mold remains closed. The hooks may be pulled from the cavities after cooling. Geometry of the hooks may therefore be somewhat limited as they must be extractable from a closed mold. (See, for instance, U.S. Pat. Nos. 3,312,583 and 3,541,216 to Rochlis; U.S. Pat. Nos. 4,775,310 and 4,794,028 to Fischer; and U.S. Pat. No. 5,393,475 to Murasaki.)        Extruding a web of material with a series of rails of hook-like cross section, running parallel along the top surface of the web. The rails may be cross-cut intermittently down to the base material. The base material may be stretched to obtain spacing between the hook elements. (See for instance, U.S. Pat. Nos. 3,665,504 and 3,735,468 to Erb.)        Extruding a web of material with a series of molded pins or similar elements and post-forming the elements into a hook type or mushroom type fastener. (See for instance, U.S. Pat. Nos. 3,182,589: 3,270,408; 5,607,635; 5,755,015; 5,781,969 and 5,792,408.)        
One common theme among all of these processes is the melting and feeding of thermoplastic material through an extruder or similar device. Although often considered efficient methods for the production of touch fasteners, extrusion/molding technologies may typically require significant investment in capital equipment (extruders, chillers, pumping systems, dryers, pellet transport systems), high process energy consumption, handling and pre-drying of raw materials, proper disposal of purging/cleaning materials and startup materials, the ventilation of noxious gases, etc. and the ability to wind rolls or otherwise process finished product non-stop.
A need exists for a method and apparatus to prepare hook type fastener elements for use in a closure system, particularly a reusable closure system, without the high capital investment and material inefficiencies as described above.